1. The problem statement, all variables and given/known data A block of mass M = 15 kg moves with velocity V and explodes at the origin into two pieces of masses m1 = 10 kg and m2 = 5 kg. The piece m1 moves in the positive direction of y axis with speed v1 = 4.5 m/s, whereas the other piece m2 moves in the positive direction of x-axis with speed v2 = 8 m/s. a) What is the velocity (magnitude and direction) of the center of mass before and after the explosion? b) How much energy is released in the explosion? 2. Relevant equations 3. The attempt at a solution a) V1=4.5j m/s , V2=8i m/s, m1=10 kg , m2= 5 kg , M=15 kg Vcomx=(8*5)/15=2.67 m/s Vcomy=(4.5*10)/15=3 m/s Vcom=sqrt(2.67^2+3^2)=4 m/s before = after ( is this statement right ?? ) b) .5*M*V^2=120 J the released energy ,, is that right ?? and another question ,, the energy before explosion = after if there is no external force right ?